Catalytic Combustion for Heat Production and Environmental Protection

Processes and apparatuses for catalytic combustion of fuels for heat production and for treatment of wastes for environment protection are described. Special attention is paid to processes of treatment of mixed radioactive organic waste in a fluidized catalyst bed and for environmentally safe catalytic technology for the utilization of liquid rocket fuel unsymmetrical dimethylhydrazine (UDMH) and wastes, containing it

The development of purifying technology of process waters of gas condensate field from methanol

The possibility in principle of methanol deep catalytic oxidation in water up to MPC has been confirmed by gas chromatography method. Oxidation process of methanol contained in vat residue after regeneration stage in concentrations of 1, 5 wt. % and less, at metal oxide catalysts at Al2O3 is considered. The basic flow diagram of closed technological cycle of methanol extraction from process waters of gas condensate fields is proposed. It consists in methanol regeneration with further deep catalytic oxidation of methanol residue quantit

Catalytic Alkylation of Brown Coal and Peat

The alcohol alkylation of low-grade metamorphic coal and peat in the presence of mineral and organic acids was studied using FTIR, NMR, and GC-MS. The impact of the reaction conditions on the yield of extractable matter was investigated experimentally, and relevant regression equations were obtained. Changes in the group and individual compositions of the wax fractions of bitumen in the process of brown coal and peat alkylation were studied. It was found that the esters of alkylated coal waxes consisted of native esters of fatty acids, and alkyl esters of these acids formed as a result of the alkylation reaction. Esterification and transesterification were predominant in the reactions of the bitumen fraction components. The positive effect of alcohol alkylation on the increase of the bitumen yield was found

Control of Ni/Ce1-xMxOy catalyst properties via the selection of dopant M = Gd, La, Mg Part 1. Physicochemical characteristics

To elucidate the role of support composition in autothermal reforming of ethanol (ATR of C2H5OH), a series of Ni catalysts (Ni content 2–15 wt.%) supported on different ceria-based oxides (Ce1-xGdxOy, Ce1-xLaxOy and Ce1-xMgxOy; x = 0.1–0.9) were prepared. The synthetized materials were tested in ATR of ethanol at 200–700 °C. It was established that supports themselves show catalytic activity in ATR of C2H5OH and provide 10–15% yield of H2 at 700 °C. Upon the increase of Ni content from 2 to 15 wt.% the temperature of 100% ethanol conversion decreases from 700 tо 300 °С, hydrogen yield increases from 25 to 60%, the inhibition of С2-С3 by-products formation, as well as the promotion of decomposition of acetaldehyde occur. The enhancement of catalyst performance in ATR of C2H5OH has been observed in the next series of supports: Ce1-xMgxOy < Ce1-xGdxOy < Ce1-xLaxOy and with a decrease of x to an optimal value that correlates with the improvement of Ni active component reducibility. At 600 °C on 10Ni/Ce0.8La0.2O1.9 catalyst the H2 yield of 50% was achieved at C2H5OH conversion of 100%. Stable and high performance of developed catalysts in ATR of C2H5OH indicates the promise of their use in the production of hydrogen

Determination of 2,4,6-Trinitrotoluene in Wastes and Sewage Water from Mining Industry by Chromato-Mass Spectrometry

A method for determination of 2,4,6-trinitrotoluene in geoenvironmental subjects by gas chromatography with mass-spectrometric detection was proposed. The distribution of 2,4,6-trinitrotoluene in wastes and sewage water samples from mining plants was studied. The presence of this compound in surface water was established. Other nitrogen-containing compounds, in particular, 2-amino-4,6-dinitrotoluene and 2,4,-dinitrotoluene, were also identified in the studied samples. The 2,4,6-trinitrotoluene (TNT) is the most important shattering explosive used for blasting out. This compound is highly toxic and stable to biodegradation. The TNT belongs to the second hazard class (highly hazardous); its maximum permissible concentration (MPC) in drinking water sources was strongly restricted, from 0.5 to 0.01 mg/L. A method for determination of 2,4,6-trinitrotoluene in surface water, sewage water and wastes by gas chromatography with mass-spectrometric detection has been developed. The TNT calibration curve was shown to be linear over the concentration range of 1.6-160 μg/mL, and the correlation factor of the line was equal to 0.997. The distribution of 2,4,6-trinitrotoluene in sewage water and wastes from mining plants has been studied. Mine water in the case of underground mining has high TNT concentrations, which cannot be decreased by the existing traditional methods of sewage water treatment. TNT is detected also in surface water after mine water disposal. Note that the TNT concentrations can exceed many times the maximum permissible concentrations prescribed for water works system. 2-amino-4,6-dinitrotoluene and 2,4,-dinitrotoluene, which can be considered as products of TNT metabolism, were also identified in the studied samples. The developed method and results of the present study make it possible to introduce the quantitative  determination of TNT and its metabolites into the programs for monitoring of surface water, sewage water and wastes in the mining plant sites in different countries as well in Russia, namely in Kuzbass

Control of Ni/Ce1-xMxOy Catalyst Properties Via the Selection of Dopant M = Gd, La, Mg. Part 2. Catalytic Activity

To elucidate the role of support composition in autothermal reforming of ethanol (ATR of C2H5OH), a series of Ni catalysts (Ni content 2–15 wt.%) supported on different ceria-based oxides (Ce1-xGdxOy, Ce1-xLaxOy and Ce1-xMgxOy; x = 0.1–0.9) were prepared. The synthetized materials were tested in ATR of ethanol at 200–700 °C. It was established that supports themselves show catalytic activity in ATR of C2H5OH and provide 10–15% yield of H2 at 700 °C. Upon the increase of Ni content from 2 to 15 wt.% the temperature of 100% ethanol conversion decreases from 700 tо 300 °С, hydrogen yield increases from 25 to 60%, the inhibition of С2-С3 by-products formation, as well as the promotion of decomposition of acetaldehyde occur. The enhancement of catalyst performance in ATR of C2H5OH has been observed in the next series of supports: Ce1-xMgxOy < Ce1-xGdxOy < Ce1-xLaxOy and with a decrease of x to an optimal value that correlates with the improvement of Ni active component reducibility. At 600 °C on 10Ni/Ce0.8La0.2O1.9 catalyst the H2 yield of 50% was achieved at C2H5OH conversion of 100%. Stable and high performance of developed catalysts in ATR of C2H5OH indicates the promise of their use in the production of hydrogen

Mesoporous Carbon-Based Rhodium Catalysts for Benzene Hydrogenation

Two different carbons, namely CAS-P-500 and CRH-P-500, were prepared from apricot stones and rice husk by H3PO4-activation at 500 ºC and H3PO4/precursor (wt/wt) impregnation ratio of 2:1 followed by water washing and desilication by NaOH solution respectively. Elemental analyses of both samples using X-ray fluorescence spectroscopy and VARIO ELEMENTAR III elemental analyzer detected up to 1% of remained phosphorus and about 88% of carbon. SEM characterization and nitrogen adsorption data revealed that highly mesoporous materials were obtained. According to BJH scheme calculations, N2 BET-surface area and pore volume for CAS-P-500 reached the values of 2030 m2/g and 1.64 cm3/g, while for CRH-P-500: 1690 m2/g and 1.95 cm3/g respectively. Activated carbons CAS-P-500 and CRH-P-500 were used as catalyst supports for the conversion of small amounts of benzene into cyclohexane to obtain cleaner gasoline. According to Euro-3 standards, gasoline should contain less than 1% of benzene, since the incomplete combustion of gasoline, which contains benzene, leads to formation of benzopyrene- a powerful carcinogen in exhaust gases. The activity of rhodium catalysts based on the CAS-P-500 and CRH-P-500 allow complete conversion of benzene into cyclohexane at 40 atm and 80oC temperature and is comparable to those of based on conventional carbons: “Sibunit”, etc

Structural Changes of Mo/ZSM-5 Catalysts During the Methane Dehydroaromatization

The structure changes of Mo/ZSM-5 catalysts with different Mo content (2 and 10 wt. % Mo) and Si/Al atomic ratio (17, 30 and 45) during the methane dehydroaromatization have been investigated by X-ray powder diffractometry, N2 adsorption and transmission electron microscopy. The treatment of Mo/ZSM-5 catalysts in reducing atmosphere (CH4 or H2) at about 700 oC promotes development of mesoporous system. The pores are open to the exterior of the zeolite grain and have an entrance diameter of ~ 4-10 nm. It is proposed that mesopore formation in Mo/ZSM-5 catalyst is connected with the dealumination of zeolite. The mesopore formation in the parent H-ZSM-5 zeolite by NaOH treatment does not improve the activity of /ZSM-5 catalyst

Support and Catalyst for the Alkylation of Benzene by Ethylene Process

A method for preparation of a spherical alumina support with preset porous structure for a catalyst of benzene alkylation with ethylene has been developed. The process of the support manufacture has been adjusted in a pilot installation, and an industrial installation for production of alumina support for the alkylation catalyst has been designed and built at the Shevchenko Plastics Plant (Aktau, Kazakhstan)

Deactivation and Regeneration of Mo/ZSM-5 Catalysts for Methane Dehydroaromatization

The methane dehydroaromatization (DHA) was studied over a series of impregnated Mo/ZSM-5 catalysts with different molybdenum contents (1-10 wt.%). It was shown that total methane conversion was decreased by 30% during 12 h of DHA reaction. The benzene formation rate was increased from 0.5 to 13.9 mol C6H6/(gMo·s) when the molybdenum content in the catalyst was lowered from 10 to 1 wt.%. The deactivated Mo/ZSM-5 catalysts were studied by a group of methods: N2 adsorption, XRD, TGDTA, HRTEM and XPS. The content and condensation degree (C/H ratio) of the carbonaceous deposits was found to increase with an increase of either of the following parameters: molybdenum content (1-10 wt.%), reaction temperature (720-780 °C), space velocity (405-1620 h-1), reaction time (0.5-20 h). The stability of Mo/ZSM-5 catalysts in reaction-regeneration cycles was better when the time on stream was shorter. The regeneration conditions of deactivated Mo/ZSM-5 catalysts providing their stable operation under multiple reaction-regeneration cycles have been selected